Harrow



R. W. HARDIE.

Patented M11124, 1890.

(No Mod e1) HARROW- I @6 JNVENTOR W] T NESSE S zww Y ent points.

UNITED STATES PATENT OFFICE.

ROBERT W. I-IARDIE, OF ALBANY, NEXV YORK.

HARROW.

SPECIFICATION forming part of Letters Patent No. 422,406, dated March 4,1890.

Application filed June 25, 1889. Serial No. 315,521. (No model.) a

T0 CLZZ whom it may concern:

Be it known that 1, ROBERT W. HARDIE, a citizen of the United States, residing at Albany, in the county of Albany and State of New York, have invented certain new and useful Improvements in Harrows, of which the following is a specification.

The object of my invention is to raise the bending-point of a curved spring harrowtooth of the'class illustrated herein, so that when the working end of the tooth comes in contact with an obstacle in its path it will rise upward in the arc of a circle over the obstacle and immediately descend on the other side, instead of being drawn backward in a straight line. This I accomplish by the means illustrated in the accompanying drawings,in which--- Figure 1 represents a perspective'view of a spring harrow-tooth embodying my invention. Fig. 2 represents a perspective view of a harrow-tooth embodying a modification of my invention. Fig. 3 represents a spring harrowtooth curved transversely at the central longitudinal line. Fig. 4 represents a spring harrow-tooth of ordinary construction attached to a bar of a barrow-frame.

A represents a spring harrow-tooth constructed of broad flat spring metal provided 011 its fastening end with a transverse curvature, which gradually diminishes into a straight transverse line. I prefer to begin to decrease the depth of said curvature at a point just beyond the fastening-point of the tooth, (represented by a in Fig. 1.) This transverse curvature makes the tooth rigid in proportion to the depth of said curvature, and the flexibility of the tooth is thereby varied at differ- When a tooth of ordinary construction such as is represented by O in Fig. 4-meets an obstacle in its path, the working end of the tooth is drawn backward a considerable distance in a substantially horizontal plane, as indicated by the dottedlines in said figure, thereby causing a useless strain upon the team, and when the working end is finally released it springs back again in substantially a horizontal line to compensate for the previous backward pull on the point, and in so doing the tooth skips over a considerable portion of the ground without cultivating it.

WVhen the shank is stiffened by the transverse curvature, the tooth does not bend'from a point low down, as indicated by the dotted lines in Fig. 4, but at a more flexible point located higher up on the tooth, and abackward pull on the free end of the tooth does not in such instances cause a backward movement of the point; but instead of this the point moves vertically in the arc of a circle with the bending-point as a center, and thereby rides over the obstacle without any unnecessary backward pull 011 the team and downward into the ground as soon as it has passed 1. A harrow-tooth made of spring metal curved upward from its point of attachment to the barrow-frame, then rearward and down- Ward to its point of contact with the ground,

and having the bending-point nearest the fast enin g end elevated above the horizontal plane of the tooths attachment to the harrow frame by means of a gradually-decreasin g transverse curvature formed on the fastening end of the tooth, substantially as shown and described.

2. A harrow-tooth of spring metal curved Y so that the main portion of the tooth shall be located above the horizontal plane of the tooths attachment to the barrow-frame, and provided with a transverse curvature extending from the point of the tooths attachment to the barrow-frame well into the bending portion of the tooth and gradually diminishing into a straight transverse line, substantially as shown and described.

3. A barrow-tooth made of spring metal curved upward from its point of attachment to the barrow-frame, then rearwardabove said frame and downward to its point of corn tact with the gron1nl,and provided with a straight transverse line, substantially as transverse curvature extending from the fastshown and described. ening end of the tooth Well into the bending portion thereof, said transverse curvature ROBERT V. HARDIE. 5 beinggradually diminished from the point of Vv'itnesses:

the tooths attachment to the barrow-flame CHAS. B. TEMPLETON,

upward and backward into a substantially MARIA L. DORIS. 

